Remember Bill Ackman’s 40% Hedge Fund Gain in 2014? It’s All Gone.

Billionaire investor William Ackman has managed to erase his entire 40% return of 2014, a performance that put him at the pinnacle of the hedge fund world.

Ackman 's Pershing Square Holdings portfolio has lost 17.3% so far in 2016, the fund told investors on Wednesday. Added to last year, when it lost 20.5% in a relatively flat year for markets, the fund's declines are now greater than its 2014 gain.

Valeant Pharmaceuticals, which was Ackman 's main loser in 2015, was also to blame for this year's drop. Valeant's stock declined 16% from Feb. 17 through Tuesday amid questions over its earnings, providing the final bit of fuel for Ackman 's fund to burn through its gains.

Valeant, which has been part of Ackman 's portfolio for only a year, on Tuesday said it would restate earnings after having prematurely accounted for some revenue, news which drove the stock to pare recent losses.

Pershing Square Capital Management, which now oversees $12 billion, did not detail exactly what caused its most recent losses and a spokesman declined to comment.

For investors who got in before the 2014 gains, Ackman 's record remains strong with his flagship Pershing Square International fund still earning an average 12% a year over the last decade.

"Long term, Bill Ackman has still made a lot of people a lot of money and they will likely stick with him, having known that a ride with him can be pretty up and down," said one long-term investor.

For clients who added money after 2014, helping Pershing Square's portfolios grow to roughly $20 billion, the story could be more nuanced.

Ackman , one of the industry's most prominent activist investors, said in January that redemption requests had been modest late last year when losses were already piling up.

So far, activist investors are performing roughly in line with the average hedge fund, which lost an average 3% in the last 12 months, data from Hedge Fund Research show. In the same period, the broader stock market had bigger losses, with the Standard & Poor's 500 index down nearly 9%.

Despite lackluster returns, investors continue to put money into hedge funds, saying they are performing relatively better than many other asset classes including stocks.

Renowned for his brash investing tactics and unwavering self-confidence, Ackman adopted a new tone in his most recent letter to clients, saying he entered the new year humbled and having learned a number of hard lessons.

"In 2016, we would like to generate results that reinforce the confidence side of the equation. Humility and skepticism will help get us there," he wrote.